In the art a number of various slicing devices of the type mentioned above are well-known. Among the manufacturers of such slicing apparatuses are CP Food Machinery, GEBA Maschinentechnik and others. Common for all these prior art apparatuses is the fact that the fillet to be treated is placed on a conveyor which will transport the fish fillet past a cutting arrangement where the fish fillet is sliced according to predetermined parameters. As the fillet passes the cutting arrangement, the slices will more or less be maintained in the shape of the original fish fillet and eventually be transferred to a board typically a piece of cardboard covered with a silver or gold look-alike finish. After this, the sliced fillet is vacuum-packed and sold for consumption.
Although a wide variety of meat products may be used with the slicing apparatus as described above they find widespread use when slicing fish fillets and in particular salmon and halibut fillets which may have been pre-treated before the slicing process.
In order to be able to slice the fish products quickly enough, a set of reciprocating knives is used which reciprocating knives are forced through the meat of the fillet towards a cutting land. The cutting land is typically a plastic construction in which a groove is formed such that as the knife passes through the fish meat, it will be able to penetrate slightly into the cutting land due to the provision of a groove. When the angle between the knife's cutting plane and the land is initially adjusted a zero-point is created. This zero-point is the optimal position/angle of the knives relative to the cutting land where the knives of the cutter are at the closest with the cutting land such that a clear, clean and finished cut may be achieved during production. However, during the process of cutting fillets it is desirable to be able to change the cutting angle. As the cutting angle is changed, the relationship between the cutting land and the knives also changes whereby the zero-point is no longer achievable, whereby a lesser cutting result is achieved.
In order to optimize the output of the single fillet it is desirable to be able to change the cutting angle during cutting of each single fillet, and it has therefore been tradition to adjust the zero-point such that the major part of the slices, typically the slices in a middle region of the fish fillet, have optimum cutting conditions.
An important part of the process of cutting fish is that the knives are sharp, provided with the correct edge characteristics depending on the consistency of the fish meat and are maintained at a high degree of cleanliness for hygienic reasons.
Stopping the machine and replacing the knives may be a relatively cumbersome process which takes a relatively long time in that the prior art knives in one end are provided with a welded-on nut such that engagement means on the arms connected to the reciprocating motor means which will make the knives move in a reciprocating manner relative to each other are likewise provided with an aperture. By superposing the aperture on the nut welded to the knife and inserting a bolt through the aperture connecting the thread inside the nut welded to the knives, it is possible to fasten the knives to the reciprocating arm. As the reciprocating mechanism is traditionally maintained inside the machine, it is often also necessary to lift or remove a cover in order to gain access to the bolts that need to be unscrewed in order to release the knives when replacing the knives.